Idiopathic or “Old Dog” Vestibular Disease

A fairly common reason for a veterinary visit is the concern that an older dog has had a stroke, when he suddenly starts walking like a drunken sailor with his head tilted. I know of other cases, where these sorts of symptoms are assumed to be a brain tumor and the dog is euthanized—maybe unnecessarily. (The condition plays a role in the new Hallmark movie, Duke.)

Well, I want to shed some light on a much more common and less concerning cause of these and other disturbing signs, something known as idiopathic vestibular disease, in case it is something you ever experience with your own geriatric dog.

Idiopathic (meaning unknown cause, think: idiot) vestibular disease is a syndrome that looks really, really bad, but usually gets better all on its own with little or no treatment.

The vestibular system
The vestibular system is composed of portions of the brain and ear and is responsible for maintaining a sense of balance. When something goes wrong with this system, it’s like being drunk on a rocky boat. Dogs with idiopathic vestibular disease have some combination of the following signs:

Now for the caveat: These clinical signs are unfortunately not unique, or diagnostic for, idiopathic vestibular disease and other things can cause this same presentation. These can include (yes) a brain tumor, an inner ear infection, inflammatory disease or sudden bleeds into the brain—to name a few. But with that being said, when the symptoms seemingly appear out of nowhere in an older dog, I always recommend a “wait-and-see approach,” treating symptomatically and supportively, as there is a good chance of improvement.

Wait-and-see approach
For a dog showing the above signs, I first discuss the possible causes. Next, I recommend blood work and a blood pressure check to make sure there is no “obvious” disease. I discuss the availability of an MRI to evaluate the inner ear and brain. Although an MRI allows for the best evaluation of disease, it is often not pursued due to cost (about $1,500 here in the Bay Area).

I examine both ear canals, and if an infection is suspected, I discuss antibiotic therapy, as inner ear disease is one of the possible causes of vestibular signs. The inner ear (pictured below) is something you cannot see during an exam because the eardrum obscures the view to the inner ear. The eardrum is like a closed door that sits in front of the middle and inner ear. However, if there is a nasty looking outer ear and an inflamed eardrum, there is a chance that inner ear disease could be present as well.

If the dog’s clinical signs are so severe that they cannot walk, I then recommend supportive care with IV fluids and injectable anti-nausea medications. Urinary catheters are sometimes placed for hygienic reasons. If clinical signs are mild, pets can often be managed at home with over-the-counter meclizine (for the feelings of “motion sickness” they experience). We also provide instructions for general nursing care as well as how to protect from falls.

The conversation ends with discussing a very loose rule of thumb: If there is gradual or complete improvement within 72 hours, it is likely idiopathic vestibular disease and additional diagnostic testing is not necessary. If there is no improvement or progression of signs, it is likely something much more serious, such as a tumor, and an MRI would be recommended to reach a definitive diagnosis. With idiopathic vestibular disease, marked improvement is usually evident in this time frame, with the pet returning to normal in 7 to 14 days (although in some dogs, a head tilt will still persist).

It should also be noted that this is not a painful condition, and my recommendations stem from the fact that euthanasia is a permanent decision, so why not wait and see, giving time a chance? There is a high likelihood that improvement will be seen and the difficult decision of euthanasia can always be made at a later date if there is no improvement or if there is a change in your pet’s quality of life. I feel there is reason to hold out hope and be cautiously optimistic, as idiopathic vestibular disease is the most common form of vestibular disease in dogs. It is the direction I would take if it were my own boy experiencing this.

Please note: There are times, however, when a physical exam points undeniably to a brain tumor, but these neurological exam findings are beyond the scope of discussion, so feel free to ask me any questions.

Veterinarian Shea Cox has enjoyed an indirect path through her professional life, initially obtaining degrees in fine arts and nursing. She later obtained her veterinary medical degree from Michigan State University in 2001 and has been practicing emergency and critical care medicine solely since that time. In 2006, she joined the ER staff at PETS Referral Center in Berkeley and cannot imagine a more rewarding and fulfilling place to spend her working hours. In her spare time, she loves to paint, wield her green thumb, cook up a storm and sail. Her days are shared with the three loves of her life: her husband Scott and their two Doberman children that curiously occupy opposite ends of the personality spectrum.